Stories of valuable finds abound, like the rare Chinese bowl bought at a tag sale for $3 and auctioned off last year for $2.225 million. Sure, it's unlikely your old junk is worth quite that much. But it could be more valuable than typical yard sale profits imply. (The average item is priced at just 85 cents, according to Signs.com, and 42 percent of yard-sale shoppers say they expect to negotiate.)

Check out the video above for some clutter categories worth researching ahead of time. Trade-in programs and secondhand sites may offer more for certain items than you'd get from individual bargain hunters. Even a few "finds" of your own can add up over multiple closets cleaned and junk drawers sorted.

Case in point: Electronics. There are dozens of trade-in programs from manufacturers, retailers and independent trade-in sites. To name just a few: Apple, Amazon, Best Buy, NextWorth.com and Gazelle.com. Amazon offers as much as $30 for a year-old Garmin GPS; a Blackberry Bold is worth $30 at NextWorth.com. Even gadgets without power cords, or with cracked screens, may have some value.

Sites typically offer free shipping to send in your stuff, and retailers allow in-store trade-ins for shoppers who want their cash or store credit quickly. Most promise to wipe your gadget of personal content, but it's still a smart idea to clear it yourself first.